Inhibition of return at different eccentricities in visual field under three-dimensional (3D) world

2017 ◽  
Vol 49 (6) ◽  
pp. 723
Author(s):  
Aijun WANG ◽  
Xiaole LIU ◽  
Xiaoyu TANG ◽  
Ming ZHANG
Keyword(s):  
Visual Field ◽  
Inhibition Of Return ◽  
Three Dimensional

scholarly journals Collaborative Pursuit-Evasion Strategy of UAV/UGV Heterogeneous System in Complex Three-Dimensional Polygonal Environment

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Xiao Liang ◽  
Honglun Wang ◽  
Haitao Luo
Keyword(s):  
Visual Field ◽  
Heterogeneous System ◽  
Three Dimensional ◽  
Unmanned Ground Vehicle ◽  
Worst Case ◽  
Ground Vehicle ◽  
Pursuit Evasion ◽  
Evasion Game ◽  
Evasion Strategy ◽  
Aerial Vehicle

The UAV/UGV heterogeneous system combines the air superiority of UAV (unmanned aerial vehicle) and the ground superiority of UGV (unmanned ground vehicle). The system can complete a series of complex tasks and one of them is pursuit-evasion decision, so a collaborative strategy of UAV/UGV heterogeneous system is proposed to derive a pursuit-evasion game in complex three-dimensional (3D) polygonal environment, which is large enough but with boundary. Firstly, the system and task hypothesis are introduced. Then, an improved boundary value problem (BVP) is used to unify the terrain data of decision and path planning. Under the condition that the evader knows the position of collaborative pursuers at any time but pursuers just have a line-of-sight view, a worst case is analyzed and the strategy between the evader and pursuers is studied. According to the state of evader, the strategy of collaborative pursuers is discussed in three situations: evader is in the visual field of pursuers, evader just disappears from the visual field of pursuers, and the position of evader is completely unknown to pursuers. The simulation results show that the strategy does not guarantee that the pursuers will win the game in complex 3D polygonal environment, but it is optimal in the worst case.

Quick phases control ocular torsion during smooth pursuit

2011 ◽  
Vol 106 (5) ◽  
pp. 2151-2166 ◽  
Author(s):  
Bernhard J. M. Hess ◽  
Jakob S. Thomassen
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Rotation Axis ◽  
Three Dimensional ◽  
Oculomotor Control ◽  
Visually Guided ◽  
Open Questions ◽  
Spatial Frequencies ◽  
Eye Rotation ◽  
Smooth Tracking

One of the open questions in oculomotor control of visually guided eye movements is whether it is possible to smoothly track a target along a curvilinear path across the visual field without changing the torsional stance of the eye. We show in an experimental study of three-dimensional eye movements in subhuman primates ( Macaca mulatta) that although the pursuit system is able to smoothly change the orbital orientation of the eye's rotation axis, the smooth ocular motion was interrupted every few hundred milliseconds by a small quick phase with amplitude <1.5° while the animal tracked a target along a circle or ellipse. Specifically, during circular pursuit of targets moving at different angular eccentricities (5°, 10°, and 15°) relative to straight ahead at spatial frequencies of 0.067 and 0.1 Hz, the torsional amplitude of the intervening quick phases was typically around 1° or smaller and changed direction for clockwise vs. counterclockwise tracking. Reverse computations of the eye rotation based on the recorded angular eye velocity showed that the quick phases facilitate the overall control of ocular orientation in the roll plane, thereby minimizing torsional disturbances of the visual field. On the basis of a detailed kinematic analysis, we suggest that quick phases during curvilinear smooth tracking serve to minimize deviations from Donders' law, which are inevitable due to the spherical configuration space of smooth eye movements.

Responses of the teleostean nucleus isthmi to looming objects and other moving stimuli

2006 ◽  
Vol 23 (2) ◽  
pp. 209-219 ◽  
Author(s):  
SHAWN P. GALLAGHER ◽  
DAVID P.M. NORTHMORE
Keyword(s):  
Visual Field ◽  
Neural Activity ◽  
Three Dimensional ◽  
Object Motion ◽  
Activity Levels ◽  
Nucleus Isthmi ◽  
Spike Density ◽  
Ball Size ◽  
Longitudinal Body Axis ◽  
The Right

Visually evoked extracellular neural activity was recorded from the nucleus isthmi (NI) of goldfish and bluegill sunfish. When moving anywhere within the right eye's visual field, three-dimensional checkered balls or patterns on a computer screen evoked bursts of spikes in the left NI. Object motion parallel to the longitudinal body axis gave responses that habituated markedly upon repetition, but movement into recently unstimulated regions of the visual field gave vigorous responses. Thus, while NI's response is not visuotopic, its habituation is. An object approaching the animal's body generated a rising spike density, whereas object recession generated only a transient burst. During the approach of a checkered stimulus ball, average NI spike density rose linearly as the ball-to-eye distance decreased and at a rate proportional to the ball's speed (2.5–30 cm/s). Increasing ball size (2.2–9.2 cm) did not affect the rate of activity rise at a given speed, but did increase overall activity levels. NI also responded reliably to expanding textures of fixed overall size. The results suggest that NI signals changes in motion of objects relative to the fish, and estimates the proximity of approaching objects.

Relative Height on the Picture-Plane and Depth Perception

1965 ◽  
Vol 21 (1) ◽  
pp. 227-236 ◽  
Author(s):  
Bruce E. Dunn ◽  
Gary C. Gray ◽  
Douglas Thompson
Keyword(s):  
Visual Field ◽  
Depth Perception ◽  
Three Dimensional ◽  
Picture Plane ◽  
Reference Plane ◽  
Two Dimensional ◽  
Relative Height ◽  
Vertical Separation ◽  
Response Set

Geometric considerations of the two-dimensional projection of the three-dimensional visual field led to hypotheses about the possible effect on depth perception of: relative height in the picture plane, the type of supplied reference plane, and angle of regard. In three experiments Ss viewed pairs of equidistant, horizontal rods in front of one of four backgrounds, with either an upward or downward angle of regard. The results confirm the hypothesis that relative height can operate to influence depth perception, that the type of background influences depth perception in the predicted direction, and that a response set resulting in a tendency for Ss to see higher objects as farther irrespective of the reference plane also occurs. The effects of angle of regard and of degree of vertical separation were not completely elucidated.

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